JP2021122933A - Machine tool and workpiece processing method - Google Patents

Abstract

To provide a machine tool which attains good workpiece processing accuracy when a workpiece is processed by using a tool held by a revolvable tool holding part, and to provide a workpiece processing method.SOLUTION: A machine tool includes: a workpiece spindle 111 which holds a workpiece and causes the workpiece to rotate around a center axis 201 extending in a horizontal direction; a tool spindle 121 which has a supported part 21, holds a tool, and may revolve around a center axis 204 orthogonal to the center axis 201; and a position holding mechanism part 26 (facing workpiece spindle 116) which has a supporting part 27 (second chuck mechanism 118) which supports the supported part 21 when the workpiece held by the workpiece spindle 111 is processed by the tool held by the tool spindle 121 and holds a position of the tool spindle 121 in a circumferential direction of the center axis 204.SELECTED DRAWING: Figure 2

Description

The present invention relates to machine tools and methods of machining workpieces.

For example, Japanese Patent Application Laid-Open No. 2014-161941 (Patent Document 1) describes a tool spindle that holds a machining tool and rotates the machining tool around a rotation axis, a tool spindle holder that supports the tool spindle, and a vertical tool. A processing apparatus including a motor that swivels and drives a tool spindle holder around a swivel shaft extending in a direction is disclosed. In the machining apparatus disclosed in Patent Document 1, the amount of deflection of the machining tool is estimated, and the rotation axis of the machining tool in the tool spindle holder is adjusted so that the angular deviation of the work surface of the work is offset.

Japanese Unexamined Patent Publication No. 2014-161941

In some cases, a long tool such as a long boring bar is held by a tool holding portion such as a tool spindle capable of turning the B-axis, and the work is machined using the long tool. In such a case, the tool holding portion may unintentionally rotate due to the influence of the tool's own weight or the reaction force applied to the tool from the work during machining of the work. This causes a problem that the machining accuracy of the work is lowered.

Therefore, an object of the present invention is to solve the above-mentioned problems, and a machine tool and a machine tool capable of obtaining good machining accuracy of a workpiece when machining a workpiece using a tool held by a swivel tool holding portion. It is to provide a processing method of a work.

A machine tool according to the present invention has a work spindle capable of holding a work and rotating the work around a first axis extending in the horizontal direction, and a supported portion, holding a tool, and holding a tool. A tool holding part that can rotate around the second axis that is orthogonal to one axis, and a support part that supports the supported part when machining a work held on the work spindle by a tool held by the tool holding part. It is provided with a position holding mechanism portion that holds the position of the tool holding portion in the circumferential direction of the second axis.

According to the machine tool configured in this way, by holding the position of the tool holding part in the circumferential direction of the second axis by the position holding mechanism part, the weight of the tool or the reaction applied from the work to the tool at the time of machining the work. It is possible to prevent the tool holding portion affected by the force from unintentionally turning in the circumferential direction of the second shaft. As a result, good machining accuracy of the work can be obtained when the work is machined using the tool held by the swivel tool holding portion.

Further, preferably, the position holding mechanism portion further holds the position of the tool holding portion in the axial direction of the second axis.

According to the machine tool configured in this way, even when the reaction force applied by the tool from the work during machining of the work includes the axial component of the second axis, the position holding mechanism portion in the axial direction of the second axis. By holding the position of the tool holding portion, it is possible to maintain good machining accuracy of the work.

Further, preferably, the position holding mechanism portion is a tailstock that has a center pin as a support portion, is arranged so as to face the work spindle in the axial direction of the first axis, and can move in the axial direction of the first axis. .. The supported portion is provided with a pin hole capable of receiving the center pin. The tailstock holds the position of the tool holding portion in the circumferential direction of the second axis by inserting the center pin into the pin hole.

According to the machine tool configured in this way, by using the tailstock as the position holding mechanism part, the tool holding part unintentionally turns in the circumferential direction of the second axis with a simple configuration. Can be prevented.

Further, preferably, the position holding mechanism portion has a chuck mechanism for holding the work detachably as a support portion, is arranged so as to face the work spindle in the axial direction of the first axis, and is a shaft of the first axis. It is an opposed work spindle that can move in the direction. The opposed work spindle holds the position of the tool holding portion in the circumferential direction of the second shaft by gripping the supported portion by the chuck mechanism.

According to the machine tool configured in this way, by using the opposed work spindle as the position holding mechanism part, the tool holding part unintentionally turns in the circumferential direction of the second shaft with a simple configuration. Can be prevented.

Further, preferably, the position holding mechanism portion is a tool post on which a pin member is mounted as a support portion and can be moved in the axial direction of the first axis and the direction orthogonal to the first axis. The supported portion is provided with a pin hole capable of receiving the pin member. The tailstock holds the position of the tool holding portion in the circumferential direction of the second axis by inserting the pin member into the pin hole.

According to the machine tool configured in this way, by using the tool post as the position holding mechanism part, it is possible to prevent the tool holding part from unintentionally turning in the circumferential direction of the second axis with a simple configuration. can. Further, since the tool post used as the position holding mechanism portion can be moved in the direction orthogonal to the first axis in addition to the first axis, the positions of the tool holding portion and the position holding mechanism portion can be determined by the progress of workpiece processing. It can be adjusted to the mutual positional relationship that changes with.

Further, preferably, the supported portion has a first state that limits the relative movement of the tool holding portion and the position holding mechanism portion in the direction intersecting the first axis when the supported portion is supported by the supported portion, and the supporting portion. It has a locking mechanism that operates between a second state that allows the relative movement of the tool holding portion and the position holding mechanism portion in the direction intersecting the first axis when the support of the supported portion is released.

According to the machine tool configured in this way, when the lock mechanism operates in the second state, the relative movement of the tool holding portion and the position holding mechanism portion in the direction intersecting the first axis is allowed. Therefore, the positions of the tool holding portion and the position holding mechanism portion can be adjusted to a mutual positional relationship that changes as the work processing progresses. Further, when the lock mechanism operates in the first state, the relative movement of the tool holding portion and the position holding mechanism portion in the direction intersecting the first axis is restricted, so that the tool holding portion and the position holding mechanism portion are restricted. Positions can be maintained in a coordinated mutual positional relationship.

The work processing method according to the present invention can rotate around a work spindle that can rotate the work around a first axis extending in the horizontal direction and a second axis that is orthogonal to the first axis. This is a method of machining a work by using a machine tool provided with a tool holding portion and a steady rest device for preventing the work from running out. The machining method of the work is a process of holding the work by the work spindle, a process of holding the tool by the tool holding part, and a tool while supporting the tool held by the tool holding part by the steady rest device. It includes a process of processing the held work.

According to the machining method of the workpiece configured in this way, by machining the workpiece while supporting the tool by the steady rest device, it is affected by the weight of the tool or the reaction force applied from the workpiece to the tool during workpiece machining. It is possible to prevent the tool holding portion from unintentionally turning in the circumferential direction of the second axis. As a result, good machining accuracy of the work can be obtained when the work is machined using the tool held by the swivel tool holding portion.

Also preferably, the machine tool further comprises a turret that is movable in the axial direction of the first axis and in the direction orthogonal to the first axis. The steady rest device is mounted on the tool post.

According to the work processing method configured in this way, the tool rest can move the steady rest device according to the change in the tool position with the progress of the work processing.

As described above, according to the present invention, when machining a workpiece using a tool held by a swivel tool holding portion, a machine tool and a machining method of the workpiece can obtain good machining accuracy of the workpiece. Can be provided.

It is a front view which shows the machine tool in Embodiment 1 of this invention. FIG. 5 is a front view showing a state in which a machine tool in FIG. 1 is used to perform deep hole drilling in a work piece using a long tool. It is sectional drawing which shows the tool spindle and the opposed work spindle (the first state of the lock mechanism) in the range surrounded by the alternate long and short dash line III in FIG. It is sectional drawing which shows the tool spindle and the opposed work spindle (second state of a locking mechanism) in the range surrounded by the alternate long and short dash line III in FIG. FIG. 5 is a front view showing a state in which a machine tool according to a second embodiment of the present invention is used to perform deep hole drilling in a work using a long tool. FIG. 5 is a cross-sectional view showing a tool spindle and a tailstock (first state of the locking mechanism) in the range included by the alternate long and short dash line VI in FIG. FIG. 5 is a cross-sectional view showing a tool spindle and a tailstock (second state of the locking mechanism) in the range included by the alternate long and short dash line VI in FIG. FIG. 5 is a front view showing a state in which a machine tool according to a third embodiment of the present invention is used to perform deep hole drilling in a work using a long tool. FIG. 5 is an enlarged cross-sectional view showing a range surrounded by the alternate long and short dash line IX in FIG. It is a front view which shows the process of the work processing method in Embodiment 4 of this invention.

Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are given the same number.

(Embodiment 1)
FIG. 1 is a front view showing a machine tool according to the first embodiment of the present invention. In FIG. 1, the inside of the machine tool is shown by seeing through a cover body (splash guard) that forms the appearance of the machine tool.

With reference to FIG. 1, the machine tool 10 according to the present embodiment has a turning function in which a tool is brought into contact with a rotating work to process a work, and a milling function in which a rotating tool is brought into contact with a work to process a work. It is a multi-tasking machine with functions. The machine tool 10 is an NC (Numerically Control) machine tool in which various operations for machining a workpiece are automated by numerical control by a computer.

First, the overall structure of the machine tool 10 will be described. The machine tool 10 has a bed 136, a work spindle 111, an opposed work spindle 116, a tool spindle (first tool post) 121, and a second tool post 131.

The bed 136 is a base member for supporting the work spindle 111, the opposed work spindle 116, the tool spindle 121, the second tool post 131, and the like, and is installed on the floor surface of a factory or the like. The bed 136 is made of a metal such as cast iron.

The work spindle 111 and the opposed work spindle 116 are configured to hold the work. The work spindle 111 and the opposed work spindle 116 are provided so as to face each other in the Z-axis direction extending in the horizontal direction. The work spindle 111 and the opposed work spindle 116 are mainly provided for rotating the work during turning using a fixing tool. The work spindle 111 is provided so as to be rotatable about a central axis 201 parallel to the Z axis. The opposed work spindle 116 is provided so as to be rotatable about a central axis 202 parallel to the Z axis. The work spindle 111 and the opposed work spindle 116 are provided with a first chuck mechanism 113 and a second chuck mechanism 118 for gripping the workpiece so as to be detachable, respectively.

The work spindle 111 is fixed on the bed 136. The opposed work spindle 116 is provided so as to be movable in the Z-axis direction by various feed mechanisms, guide mechanisms, servomotors, and the like.

The tool spindle 121 and the second tool post 131 are configured to hold the tool. The tool spindle 121 is provided above the second tool post 131.

The tool spindle 121 is rotatably provided about a central axis 203 parallel to the X axis extending in the vertical direction. The tool spindle 121 is provided with a clamp mechanism (not shown) for holding the tool detachably.

The tool spindle 121 is further provided so as to be rotatable about a central axis 204 extending in the horizontal direction and parallel to the Y axis orthogonal to the Z axis direction (B-axis rotation). The turning range of the tool spindle 121 is, for example, a range of ± 120 ° with respect to a posture in which the spindle end surface 123 of the tool spindle 121 faces downward (the posture shown in FIG. 1).

The tool spindle 121 is supported on the bed 136 by a column or the like (not shown). The tool spindle 121 is provided so as to be movable in the X-axis direction, the Y-axis direction, and the Z-axis direction by various feed mechanisms, guide mechanisms, servomotors, and the like provided on the column and the like.

The second tool post 131 has a so-called turret type, and a plurality of tools are radially attached to perform swivel indexing.

More specifically, the second tool post 131 has a swivel portion 132. The swivel portion 132 is provided so as to be swivelable around a central axis 206 parallel to the Z axis. A tool holder for holding the tool is attached at a position spaced around the central axis 206 in the circumferential direction. When the swivel portion 132 swivels around the central axis 206, the tool held by the tool holder moves in the circumferential direction, and the tool used for machining the work is determined.

The second tool post 131 is supported on the bed 136 by a saddle or the like (not shown). The second tool post 131 is provided so as to be movable in the Z-axis direction and the X-axis direction orthogonal to the Z-axis direction by various feed mechanisms, guide mechanisms, servomotors, etc. provided in the saddle or the like. The second tool post 131 may be provided so as to be movable in the Z-axis direction, orthogonal to the Z-axis direction, and in the oblique vertical direction including the vertical component. In this case, the second tool post 131 is orthogonal to the Z-axis direction by being fed simultaneously in the X-axis direction and the Y-axis direction, and moves in the diagonally vertical direction including the vertical component. good.

A rotary tool or a fixing tool may be held in each of the tool spindle 121 and the second tool post 131. The rotary tool is a tool for machining a workpiece while rotating, and is a drill, an end mill, a reamer, or the like. The fixing tool is a tool for processing a rotating workpiece, and is an inner diameter cutting tool including a long boring bar described later. When the rotary tool is held on the second turret 131, the second turret 131 includes a motor that outputs rotation and a power transmission mechanism that transmits the rotation output from the motor to the rotary tool.

The machine tool 10 further includes a splash guard 210. The splash guard 210 has the appearance of the machine tool 10 and forms a processing area 200 for the work.

Although not shown in FIG. 1, an automatic tool changer (ATC: Automatic Tool Changer) for automatically changing the tool mounted on the tool spindle 121 and a tool spindle are around the work spindle 111. A tool magazine for accommodating replacement tools to be mounted on 121 is provided.

FIG. 2 is a front view showing a state in which a machine tool in FIG. 1 is used to perform deep hole drilling in a work using a long tool.

With reference to FIGS. 1 and 2, the work W is held by the work spindle 111. The tool spindle 121 is arranged at a position facing the work spindle 111 in the Z-axis direction. The tool spindle 121 is swiveled (B-axis swivel) by an angle of 90 ° about the central shaft 204 from the reference posture shown in FIG.

A long tool T such as a long boring bar is held by the tool spindle 121. The tool T projects from the spindle end surface 123 of the tool spindle 121 toward the work W in the Z-axis direction (−Z-axis direction). The tool T has a shaft portion 153 and a tip (blade portion) 151. The shaft portion 153 has a shaft shape having a circular cross section extending along the central shaft 203. A tip 151 is attached to the tip of the shaft portion 153.

While rotating the work W around the central shaft 201 by the work spindle 111, the cutting edge (tip portion of the tip 151) of the tool T held by the tool spindle 121 is brought into contact with the work W, and the tool T is further brought into contact with the work W by the tool spindle 121. Is sent toward the work W in the Z-axis direction to perform deep hole drilling in the work W. In this case, the tool spindle 121 may unintentionally rotate around the central axis 204 due to the influence of the weight of the tool T or the reaction force applied from the work W to the tool T during machining of the workpiece.

On the other hand, the tool spindle 121 has a supported portion 21. The supported portion 21 is provided on the opposite side of the spindle end surface 123 with the central shaft 204, which is the center of the B-axis rotation of the tool spindle 121, interposed therebetween. The supported portion 21 is attached to the rear end surface 125 of the tool spindle 121.

The machine tool 10 has a position holding mechanism portion 26 that holds the position of the tool spindle 121 in the circumferential direction of the central shaft 204. The position holding mechanism portion 26 has a support portion 27. The support portion 27 supports the supported portion 21 when the work W held by the work spindle 111 is machined by the tool T held by the tool spindle 121. The position holding mechanism portion 26 further holds the position of the tool spindle 121 in the axial direction of the central shaft 204 by the supporting portion 27 supporting the supported portion 21.

The opposed work spindle 116 is arranged on the opposite side of the workpiece spindle 111 with the tool spindle 121 interposed therebetween. The tool spindle 121 is arranged between the work spindle 111 and the opposed work spindle 116 in the Z-axis direction. The supported portion 21 faces the second chuck mechanism 118 of the opposed work main shaft 116 in the Z-axis direction. In the present embodiment, the opposed work spindle 116 corresponds to the position holding mechanism portion 26, and the second chuck mechanism 118 included in the opposed work spindle 116 corresponds to the support portion 27.

3 and 4 are cross-sectional views showing the tool spindle and the opposed work spindle in the range surrounded by the alternate long and short dash line III in FIG.

With reference to FIGS. 2 to 4, the second chuck mechanism 118 has a plurality of chuck claws 119. The plurality of chuck claws 119 are arranged at intervals from each other in the circumferential direction of the central axis 202. The plurality of chuck claws 119 can slide in the radial direction of the central axis 202 in synchronization with each other.

When the work W held on the work spindle 111 is machined by the tool T held on the tool spindle 121, the supported portion 21 is arranged inside the plurality of chuck claws 119. The second chuck mechanism 118 grips the supported portion 21 by sliding the plurality of chuck claws 119 inward in the radial direction of the central axis 202. As a result, the opposed work spindle 116 holds the position of the tool spindle 121 in the circumferential direction and the axial direction of the central axis 204.

According to such a configuration, the position holding mechanism portion 26 (opposing work spindle 116) holds the position of the tool spindle 121 in the circumferential direction and the axial direction of the central axis 204, whereby the weight of the tool T or the workpiece machining is performed. It is possible to prevent the tool spindle 121, which is sometimes affected by the reaction force applied to the tool T from the work W, from unintentionally turning in the circumferential direction of the central shaft 204 or moving in the axial direction of the central shaft 204. As a result, good machining accuracy of the work W can be obtained.

Subsequently, the locking mechanism provided in the supported portion 21 of the present embodiment will be described. With reference to FIGS. 3 and 4, the supported portion 21 moves relative to the tool spindle 121 and the position holding mechanism portion 26 in the direction intersecting the central axis 201 when the supported portion 21 is supported by the supported portion 27. Relative to the tool spindle 121 and the position holding mechanism 26 in the direction intersecting the central axis 201 when the support of the supported portion 21 by the support portion 27 is released from the first state (state shown in FIG. It has a locking mechanism that operates between a second state (the state shown in FIG. 4) that allows such movement.

More specifically, when the supported portion 21 is gripped by the second chuck mechanism 118, the supported portion 21 has a direction (X-axis-Y) in which the tool spindle 121 is orthogonal to the central axis 201 with respect to the opposed work spindle 116. At the time of the first state (the state shown in FIG. 3) that restricts the movement in the plane direction of the shaft) and the gripping of the supported portion 21 by the second chuck mechanism 118, the tool with respect to the opposed work spindle 116. It has a locking mechanism that operates between a second state (state shown in FIG. 4) that allows the spindle 121 to move in a direction orthogonal to the central axis 201 (plane direction of the X-axis-Y-axis).

The supported portion 21 includes a case body 31, a slide member 41, a plurality of arm members 51, and an elastic member 57.

The case body 31 is attached to the rear end surface 125 of the tool spindle 121. The case body 31 has a cylindrical shape that extends in the axial direction of the central shaft 203, opens on the rear end surface 125 side of the tool spindle 121 in the axial direction of the central shaft 203, and closes on the side of the second chuck mechanism 118. The case body 31 forms an internal space on the rear end surface 125 of the tool spindle 121. The case body 31 has a fixed pad portion 32. The fixed pad portion 32 has a flat plate shape extending inward in the radial direction of the central axis 203 from the inner peripheral surface of the case body 31 and extending in a plane orthogonal to the central axis 203. The fixed pad portion 32 is provided with an opening 33. The opening 33 is formed of a through hole penetrating the fixed pad portion 32 on the axis of the central shaft 203. The opening 33 has a circular opening shape centered on the central axis 203.

The slide member 41 is arranged inside the case body 31. The slide member 41 is supported in the case body 31 so as to be slidable in the axial direction of the central axis 203. The plurality of arm members 51 extend from the inside of the case body 31 to the outside. The plurality of arm members 51 are supported by the case body 31 so as to be slidable in the radial direction of the central axis 203.

The slide member 41 converts the operation (grip operation by a plurality of chuck claws 119) input from the opposed work spindle 116 to the supported portion 21 into a locking operation (movement of the movable pad portion 42) in the locking mechanism. The slide member 41 has a movable pad portion 42, an intermediate shaft portion 43, and a gripped portion 44. The movable pad portion 42 is arranged between the rear end surface 125 of the tool spindle 121 and the fixed pad portion 32 in the axial direction of the central shaft 203. The movable pad portion 42 extends in a disk shape around the central axis 203. The movable pad portion 42 is arranged so as to face the fixed pad portion 32 in the axial direction of the central axis 203.

The gripped portion 44 is arranged on the opposite side of the movable pad portion 42 with the fixed pad portion 32 interposed therebetween in the axial direction of the central axis 203. The gripped portion 44 is arranged inside a plurality of chuck claws 119. The gripped portion 44 has a tapered surface 44a. The tapered surface 44a is formed of a conical surface centered on the central axis 203. The diameter of the tapered surface 44a centered on the central axis 203 becomes smaller as it approaches the movable pad portion 42 in the axial direction of the central axis 203.

The intermediate shaft portion 43 connects the movable pad portion 42 and the gripped portion 44. The intermediate shaft portion 43 has a shaft shape extending on the axis of the central shaft 203. The intermediate shaft portion 43 has a circular outer shape when cut by a plane orthogonal to the central axis 203. The intermediate shaft portion 43 extends from the movable pad portion 42 through the opening 33 to the gripped portion 44.

The arm member 51 has an arm shape extending in the radial direction of the central axis 203. The plurality of arm members 51 are arranged so as to be spaced apart from each other in the circumferential direction of the central axis 203. The plurality of arm members 51 are provided at phase positions corresponding to the plurality of chuck claws 119 in the circumferential direction of the central axis 203. An elastic force (not shown) acts on the arm member 51 toward the outside in the radial direction of the central axis 203.

The arm member 51 has a tapered surface 51a. The tapered surface 51a is provided at the tip of the arm member 51 inside the central axis 203 in the radial direction. The tapered surface 51a has an inclination corresponding to the tapered surface 44a with respect to the central axis 203.

The elastic member 57 is inserted between the fixed pad portion 32 and the movable pad portion 42 in the axial direction of the central axis 203. The elastic member 57 exerts an elastic force on the fixed pad portion 32 and the movable pad portion 42 in the direction in which the fixed pad portion 32 and the movable pad portion 42 are separated from each other in the axial direction of the central axis 203. The elastic member 57 is made of, for example, a coil spring.

As shown in FIG. 3, by sliding the plurality of chuck claws 119 inward in the radial direction of the central axis 202, the gripped portion 44 is gripped via the plurality of arm members 51. At this time, when the tapered surface 51a comes into contact with the tapered surface 44a, the slide member 41 slides in the axial direction of the central shaft 203 in the direction approaching the opposed work main shaft 116. As a result, the movable pad portion 42 moves close to the fixed pad portion 32 while resisting the elastic force of the elastic member 57, and is eventually pressed against the fixed pad portion 32 in the axial direction of the central axis 203. As a result, the frictional force generated between the movable pad portion 42 and the fixed pad portion 32 causes the case body 31 and the slide member 41 to be coupled to each other, so that the opposed work spindle 116 and the tool spindle 121 are locked to each other in the first state. Is obtained.

As shown in FIG. 4, the plurality of arm members 51 are separated from the gripped portion 44 by sliding the plurality of chuck claws 119 toward the outer side in the radial direction of the central axis 202. At this time, since the tapered surface 51a is not in contact with the tapered surface 44a, the slide member 41 slides in the axial direction of the central shaft 203 in the direction away from the opposed work main shaft 116 due to the elastic force of the elastic member 57. As a result, the movable pad portion 42 is separated from the fixed pad portion 32, and the coupling between the case body 31 and the slide member 41 is released. Therefore, the facing work spindle 116 and the tool spindle 121 are unlocked from each other in the second state. Is obtained.

According to such a configuration, when the tool T is fed in the Z-axis direction while the cutting edge of the tool T is in contact with the work W, the supported portion 21 is in the first state shown in FIG. In this case, the opposed work spindle 116 holds the position of the tool spindle 121 in the circumferential direction and the axial direction of the central axis 204. On the other hand, when the cutting edge of the tool T is separated from the work W or the cutting position of the cutting edge of the tool T with respect to the work W is changed in the radial direction of the central axis 201, the supported portion 21 is shown in FIG. The second state. In this case, the tool spindle 121 can move in the radial direction of the central shaft 201 within the range in which the intermediate shaft portion 43 can move inside the opening edge of the opening 33.

In the present embodiment, the case where the tool holding portion in the present invention is the tool spindle has been described, but the present invention is not limited to this. The tool holding portion in the present invention may be, for example, a tool post capable of turning on the B axis.

(Embodiment 2)
FIG. 5 is a front view showing a state in which a machine tool according to a second embodiment of the present invention is used to perform deep hole drilling in a work using a long tool. The machine tool in the present embodiment basically has the same structure as the machine tool 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

With reference to FIG. 5, the machine tool in the present embodiment replaces the opposed work spindle 116 in FIG. 2 with a tailstock 161 for supporting the center of rotation of the work W held by the workpiece spindle 111. Have. The tailstock 161 is provided so as to face the work spindle 111 in the Z-axis direction.

The tailstock 161 is provided so as to be movable in the Z-axis direction by various feed mechanisms, guide mechanisms, servomotors, and the like. The tailstock 161 has a center pin 162. The center pin 162 extends toward the work spindle 111 on the axis of the central axis 207 parallel to the Z axis, and has a sharpened tip portion at the tip thereof.

The tailstock 161 is arranged on the opposite side of the work spindle 111 with the tool spindle 121 interposed therebetween. The tool spindle 121 is arranged between the work spindle 111 and the tailstock 161 in the Z-axis direction. The supported portion 21 faces the center pin 162 of the tailstock 161 in the Z-axis direction. In the present embodiment, the tailstock 161 corresponds to the position holding mechanism portion 26, and the center pin 162 of the tailstock 161 corresponds to the support portion 27.

6 and 7 are cross-sectional views showing the tool spindle and tailstock in the range enclosed by the alternate long and short dash line VI in FIG.

With reference to FIGS. 5 to 7, the supported portion 21 is provided with a pin hole 92. The pin hole 92 has a hole shape that can accept the center pin 162. When machining the work W held on the work spindle 111 by the tool T held on the tool spindle 121, the tailstock 161 is moved in the Z-axis direction toward the tool spindle 121 (-Z-axis direction). Inserts the center pin 162 into the pin hole 92. As a result, the tailstock 161 holds the position of the tool spindle 121 in the circumferential direction and the axial direction of the central shaft 204.

Subsequently, the locking mechanism provided in the supported portion 21 of the present embodiment will be described. With reference to FIGS. 6 and 7, the supported portion 21 includes a case body 61, a cylinder 71, a piston 91, a movable pad 79, and an elastic member 80.

The case body 61 is attached to the rear end surface 125 of the tool spindle 121. The case body 61 forms an internal space on the rear end surface 125 of the tool spindle 121. The case body 61 has a fixed pad portion 62. The fixed pad portion 62 has a flat plate shape extending in a plane orthogonal to the central axis 203. The fixed pad portion 62 is provided with an opening 63. The opening 63 is formed of a through hole penetrating the fixing pad portion 62 on the axis of the central shaft 203. The opening 63 has a circular opening shape centered on the central axis 203. The opening 63 communicates the space inside and outside the case body 61.

The piston 91 is supported by the cylinder 71 so as to be slidable in the axial direction of the central axis 203. The piston 91 is provided with the pin hole 92 described above. The pin hole 92 is opened so as to face the center pin 162 in the axial direction of the central shaft 203.

The cylinder 71 has a pad support portion 72, an intermediate shaft portion 74, and a piston support portion 73. The pad support portion 72 is arranged inside the case body 61. The pad support portion 72 has a cylindrical shape centered on the central axis 203. The pad support portion 72 is provided with a pad insertion hole 77. The pad insertion hole 77 opens facing the fixed pad portion 62 in the axial direction of the central axis 203. A movable pad 79 is inserted into the pad insertion hole 77. The movable pad 79 is provided so as to be slidable in the axial direction of the central axis 203. The pad support portion 72, together with the movable pad 79, forms a section of the hydraulic chamber 76 in which oil is sealed.

The piston support portion 73 is arranged outside the case body 61. The piston support portion 73 is provided with a piston insertion hole 82. The piston insertion hole 82 opens facing the tailstock 161 in the axial direction of the central shaft 203. A piston 91 is inserted inside the piston insertion hole 82. The piston support portion 73, together with the piston 91, forms a section of the hydraulic chamber 81 in which oil is sealed.

The intermediate shaft portion 74 connects the pad support portion 72 and the piston support portion 73. The intermediate shaft portion 74 has a shaft shape extending on the axis of the central shaft 203. The intermediate shaft portion 74 has a circular outer shape when cut by a plane orthogonal to the central shaft 203. The intermediate shaft portion 74 extends from the pad support portion 72 through the opening 63 to the piston support portion 73. The intermediate shaft portion 74 is provided with a communication hole 83. The communication hole 83 communicates the hydraulic chamber 76 and the hydraulic chamber 81.

The elastic member 80 is arranged in the hydraulic chamber 76. The elastic member 80 exerts an elastic force on the movable pad 79 in the direction of moving the movable pad 79 away from the fixed pad portion 62 in the axial direction of the central axis 203. The elastic member 80 is made of, for example, a coil spring.

As shown in FIG. 6, the center pin 162 is inserted into the pin hole 92 by moving the tailstock 161 in the Z-axis direction toward the tool spindle 121 (−Z-axis direction). At this time, the piston 91 pushed by the center pin 162 slides in the −Z axis direction, so that the oil in the hydraulic chamber 81 moves into the hydraulic chamber 76 through the communication hole 83, and the oil pressure in the hydraulic chamber 76 is released. Increase. As a result, the movable pad 79 moves close to the fixed pad portion 62 while resisting the elastic force of the elastic member 80, and is eventually pressed against the fixed pad portion 62 in the axial direction of the central axis 203. As a result, the frictional force generated between the movable pad 79 and the fixed pad portion 62 connects the case body 61 with the cylinder 71 and the piston 91, so that the tailstock 161 and the tool spindle 121 are mutually locked. The first state is obtained.

As shown in FIG. 7, the center pin 162 is removed from the pin hole 92 by moving the tailstock 161 in the Z-axis direction away from the tool spindle 121 (+ Z-axis direction). At this time, the force of pushing the piston 91 in the −Z axis direction by the center pin 162 is eliminated, and the movable pad 79 is pulled in the −Z axis direction by the elastic force of the elastic member 80. As a result, the movable pad 79 is separated from the fixed pad portion 62, and the coupling between the case body 61 and the cylinder 71 and the piston 91 is released, so that the tailstock 161 and the tool spindle 121 are unlocked from each other. The second state is obtained.

According to the machine tool according to the second embodiment of the present invention configured in this way, the effect described in the first embodiment can be similarly exhibited.

(Embodiment 3)
FIG. 8 is a front view showing a state in which a machine tool according to a third embodiment of the present invention is used to perform deep hole drilling in a work using a long tool. The machine tool in the present embodiment basically has the same structure as the machine tool 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

With reference to FIG. 8, the machine tool according to this embodiment further includes a pin member 140. The pin member 140 is attached to the second tool post 131 via the tool holder 137. The pin member 140 extends toward the work spindle 111 in the Z-axis direction and has a sharpened tip portion at the tip thereof.

The second tool post 131 is arranged on the opposite side of the work spindle 111 with the tool spindle 121 interposed therebetween. The tool spindle 121 is arranged between the work spindle 111 and the second tool post 131 in the Z-axis direction. The supported portion 21 faces the pin member 140 mounted on the second tool post 131 in the Z-axis direction. In the present embodiment, the second turret 131 corresponds to the position holding mechanism portion 26, and the pin member 140 mounted on the second turret 131 corresponds to the support portion 27.

FIG. 9 is an enlarged cross-sectional view showing a range surrounded by the alternate long and short dash line IX in FIG. With reference to FIGS. 8 and 9, the supported portion 21 is composed of a block body 22. The block body 22 is provided with a pin hole 23. The pin hole 23 has a hole shape that can accept the pin member 140. When machining the work W held on the work spindle 111 by the tool T held by the tool spindle 121, the pin member 140 is pinned by appropriately moving the second tool post 131 in the X-axis and Z-axis directions. Insert into the hole 23. As a result, the second tool post 131 holds the position of the tool spindle 121 in the circumferential direction and the axial direction of the central shaft 204.

In the present embodiment, the pin member 140 is mounted on the second tool post 131 that can move in the X-axis direction and the Z-axis direction. Therefore, by moving the second tool post 131 in synchronization with the tool spindle 121 at the time of machining the work, the state in which the pin member 140 is inserted into the pin hole 23 can be maintained.

According to the machine tool according to the third embodiment of the present invention configured in this way, the effect described in the first embodiment can be similarly exhibited.

(Embodiment 4)
FIG. 10 is a front view showing the process of the work processing method according to the fourth embodiment of the present invention. The machine tool used in the work processing method of the present embodiment basically has the same structure as that of the machine tool 10 of the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

With reference to FIG. 10, in the machine tool used in the work processing method in the present embodiment, the tool spindle 121 is not provided with the supported portion 21. The machine tool further includes a steady rest device 191 for preventing runout of the work. As an example, the steady rest device 191 includes two rollers provided at the tips of two rotatable arms and one roller provided between the roots of the two arms (1 roller). (Not shown), and is configured so that the outer peripheral surface of the work W can be supported by these three rollers.

The steady rest device 191 is mounted on a second tool post 131 that can move in the X-axis direction and the Z-axis direction.

The steady rest device 191 is arranged between the work spindle 111 and the tool spindle 121 in the Z-axis direction. The steady rest device 191 is arranged between the cutting edge of the tool T held by the tool spindle 121 and the spindle end surface 123 of the tool spindle 121 in the Z-axis direction. The steady rest device 191 is arranged between the work W held by the work spindle 111 and the spindle end surface 123 of the tool spindle 121 in the Z-axis direction.

The steady rest device 191 is arranged below the tool T (shaft portion 153) held by the tool spindle 121.

In the work machining method of the present embodiment, first, the work W is held by the work spindle 111, and the tool T is held by the tool spindle 121. More specifically, the work W is gripped by the first chuck mechanism 113, and the tool T is clamped by the clamping mechanism (not shown) on the tool spindle 121.

The process of holding the work W by the work spindle 111 and the step of holding the tool T by the tool spindle 121 are not particularly limited.

Next, the tool spindle 121 is moved to a position facing the work spindle 111 in the Z-axis direction, and the tool spindle 121 is swiveled around the central axis 204 so that the spindle end surface 123 of the tool spindle 121 in FIG. 10 is formed. Change to a posture facing the −Z axis direction. By moving the second turret 131, the steady rest device 191 mounted on the second turret 131 is moved to the above-mentioned position for supporting the tool T.

Next, the work W held by the work spindle 111 is machined by the tool T while the tool T held by the tool spindle 121 is supported by the steady rest device 191.

According to such a configuration, by machining the work W while supporting the tool T by the steady rest device 191, it is affected by the own weight of the tool T or the reaction force applied from the work W to the tool T during machining of the work. It is possible to prevent the tool spindle 121 from unintentionally turning in the circumferential direction of the central axis 204. As a result, good machining accuracy of the work W can be obtained.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The present invention is applied to, for example, a machine tool provided with a tool spindle for B-axis swivel machining, and a machining method of a workpiece executed by using such a machine tool.

10 Machine tool, 21 Supported part, 22 Block body, 23,92 pin hole, 26 Position holding mechanism part, 27 Support part, 31,61 Case body, 32,62 Fixed pad part, 33,63 Opening, 41 Slide Member, 42 movable pad part, 43,74 intermediate shaft part, 44 gripped part, 44a, 51a tapered surface, 51 arm member, 57,80 elastic member, 71 cylinder, 72 pad support part, 73 piston support part, 76, 81 Hydraulic chamber, 77 Pad insertion hole, 79 Movable pad, 82 Piston insertion hole, 83 Communication hole, 91 Piston, 111 Work spindle, 113 1st chuck mechanism, 116 Opposed work spindle, 118 2nd chuck mechanism, 119 Chuck claw, 121 Tool spindle, 123 Spindle end face, 125 Rear end face, 131 Second tool post, 132 Swivel part, 136 bed, 137 Tool holder, 140 pin member, 151 chip, 153 shaft part, 161 tailstock, 162 center pin, 191 Steering device, 200 machining area, 201,202,203,204,206,207 central axis, 210 splash guard.

Claims (8)

A work spindle that holds the work and can rotate the work around the first axis that extends in the horizontal direction,
A tool holding portion that has a supported portion, holds a tool, and can rotate around a second axis orthogonal to the first axis.
It has a support portion that supports the supported portion when the work held on the work spindle is machined by the tool held by the tool holding portion, and the position of the tool holding portion in the circumferential direction of the second shaft. A machine tool equipped with a position holding mechanism for holding a machine tool. The machine tool according to claim 1, wherein the position holding mechanism portion further holds the position of the tool holding portion in the axial direction of the second axis. The position holding mechanism portion has a center pin as the support portion, is arranged so as to face the work spindle in the axial direction of the first axis, and is a tailstock that can move in the axial direction of the first axis. can be,
The supported portion is provided with a pin hole capable of receiving the center pin.
The machine tool according to claim 1 or 2, wherein the tailstock holds the position of the tool holding portion in the circumferential direction of the second axis by inserting the center pin into the pin hole. The position holding mechanism portion has a chuck mechanism for holding the work detachably as the supporting portion, and is arranged so as to face the work spindle in the axial direction of the first shaft. It is an opposed work spindle that can move in the axial direction.
The machine tool according to claim 1 or 2, wherein the opposed work spindle holds the position of the tool holding portion in the circumferential direction of the second shaft by gripping the supported portion by the chuck mechanism. The position holding mechanism portion is a tool post on which a pin member is mounted as the support portion and can move in the axial direction of the first axis and the direction orthogonal to the first axis.
The supported portion is provided with a pin hole capable of receiving the pin member.
The machine tool according to claim 1 or 2, wherein the tool post holds the position of the tool holding portion in the circumferential direction of the second axis by inserting the pin member into the pin hole. The supported portion includes a first state that limits the relative movement of the tool holding portion and the position holding mechanism portion in a direction intersecting the first axis when the supported portion is supported by the supported portion. When the support of the supported portion is released by the supporting portion, it operates between the tool holding portion and the second state that allows the relative movement of the position holding mechanism portion in the direction intersecting the first axis. The machine tool according to any one of claims 1 to 5, which has a locking mechanism. A work spindle that can rotate the work around the first axis extending in the horizontal direction, a tool holding part that can rotate around the second axis that is orthogonal to the first axis, and a tool holding portion that can rotate the work around the first axis to prevent runout of the work. It is a method of processing a workpiece using a machine tool equipped with a steady rest device for the purpose.
The process of holding the work by the work spindle and
The process of holding the tool by the tool holding part and
A work processing method comprising a step of processing the work held on the work spindle by the tool while supporting the tool held by the tool holding portion by the steady rest device. The machine tool further includes a tool post that can move in the axial direction of the first axis and in the direction orthogonal to the first axis.
The work processing method according to claim 7, wherein the steady rest device is mounted on the tool post.

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